<p>Many disorders can affect our ability to speak and communicate. They range from saying sounds incorrectly to being completely unable to speak or understand speech. Causes include:</p><ul> <li><a href="https://medlineplus.gov/hearingdisordersanddeafness.html">Hearing disorders and deafness</a></li> <li><a href="https://medlineplus.gov/voicedisorders.html">Voice problems</a>, such as dysphonia or those caused by <a href="https://medlineplus.gov/cleftlipandpalate.html">cleft lip or palate</a> </li> <li>Speech problems like <a href="https://medlineplus.gov/stuttering.html">stuttering</a></li> <li><a href="https://medlineplus.gov/developmentaldisabilities.html">Developmental disabilities</a></li> <li><a href="https://medlineplus.gov/learningdisabilities.html">Learning disabilities</a></li> <li><a href="https://medlineplus.gov/autismspectrumdisorder.html">Autism spectrum disorder</a></li> <li><a href="https://medlineplus.gov/traumaticbraininjury.html">Brain injury</a></li> <li><a href="https://medlineplus.gov/stroke.html">Stroke</a></li> </ul> <p>Some speech and communication problems may be genetic. Often, no one knows the causes. By first grade, about 5% of <a href="https://medlineplus.gov/speechandlanguageproblemsinchildren.html">children</a> have noticeable speech disorders. Speech and language therapy can help. </p> <p class="">NIH: National Institute on Deafness and Other Communication Disorders</p>